软火花电路的本安特性及优化分析

Intrinsically safe characteristics and optimization analysis of soft-spark circuit

提出一种可以有效提高本质安全型开关电源输出功率的电路结构——软火花电路,即在开关电源等效容性电路模型的末端添加附加电感,利用电感可延缓电流变化的作用减小短路火花电压与火花电流的重叠面积(即火花功率),进而提高本安电源输出功率。为了探究软火花电路的本安特性,首先通过数学推导得到在振荡和非振荡两种状态下火花电流和火花功率的数学表达式,并利用Mathcad仿真软件分析两种状态下电容量和电感量对短路火花功率的影响,结果表明附加电感在非振荡状态范围内取值对提高本安电源输出功率具有良好的效果;然后分析附加电感对原电路电气性能的影响,结果表明附加电感的存在对原电路的启动性能和负载动态响应性能没有显著影响,在可接受范围内;接着采用粒子群算法对软火花电路在多约束条件下的功率进行最优化分析,得到火花功率最优参数值;最后通过实验验证了分析结果的正确性。

In order to improve the output power of switching power supply,a soft-spark circuit is proposed in which an appended inductor is laid at the end of the equivalent capacitive circuit model of switching power supply. As the induc- tor can delay current variation, the overlap area of spark voltage and spark current （namely the spark power） can be effectively reduced so as to improve the output power of intrinsically safe switching power supply. To investigate the in- trinsically safety performance of the soft-spark circuit, firstly, the spark current and spark power in the circumstances of oscillation and non-oscillation are respectively deduced through mathematical deduction, and the Mathcad simulation software is used to simulate the effect of capacitance and inductance on spark power, which indicates the inductance values in non-oscillation circumstance have effectively improved the output power. Secondly, the influence of the ap- pended inductance on the electrical performance of primary circuit is analyzed ,which indicates the inductance has no obvious impact on starting performance and load dynamic response performance, which is in an allowed range. Thirdly, the particle swarm algorithm is applied to analyze the power of the soft-spark circuit under more constraint so as to ob- tain power optimization value. Finally, the experiments are conducted to verify the results.